1. Field of the Invention
The present invention relates to a filter device of dripping type for extracting drinks such as coffee, tea, etc., and more particularly to the filter device comprising a container which includes a filter chamber for containing substance to be extracted such as ground coffee or the like, the container being adapted to be folded and stored in a compact state and suitable for simple treatment.
2. Description of the Related Art
There have been conventionally proposed, put into practice, and placed on market, a lot of filter devices for coffee of dripping type in which hot water is directly poured on ground coffee to extract coffee liquid.
In most of handy filter devices of disposable type for one person or a few people, ground coffee is integrally enclosed in the device in advance, and coffee liquid can be extracted simply by pouring hot water. Moreover, because the filter device of the type can be disposed of, after use, as a trash, it has been widely and conveniently used.
The filter device of this disposable type can be largely classified into two types. First is the filter device for coffee of the dripping type consisting of a filter chamber for containing ground coffee and a support for supporting and fixing the filter chamber at an edge of a coffee cup or the like, and in which coffee liquid is recovered after hot water has directly poured on the ground coffee contained in the filter chamber. Second is a filter device for coffee of tea bag type in which a filter bag containing ground coffee is dipped in hot water in a coffee cup. The former filter device of the dripping type includes a cup-like container for storing hot water in an amount corresponding to capacity of the coffee cup and the filter chamber for the ground coffee which is integrally assembled to the container. The hot water which has been once stored in the container is allowed to pass through the filter chamber to extract the coffee liquid.
However, the filter device for coffee of the dripping type has had such disadvantages that its body part formed in a cup-like shape for storing hot water is bulky, and production cost is relatively high in spite of disposable type. There has been another drawback that it is difficult to dispose of the filter device because of its material.
It has been a serious problem inter alia that the filter device of this type requires a larger space for storing, transporting or displaying in shops as compared with the coffee filter device of the tea bag type which can be folded into a compact state.
In order to solve the above described problems, there have been already proposed such coffee extractors as disclosed in Japanese Utility Model Publications Nos. 5-10766 and 5-40843.
In the former coffee extractor, a container body is provided with vertical pleats at a peripheral face of its lower half part, a folding line formed at an upper edge of the vertical pleats, and horizontal pleats in a radial direction at a stepped part which continuously forms a coffee filter chamber, thereby enabling the peripheral face of the lower half part of the container body to be folded by means of these vertical and horizontal pleats, and the folding line. In this manner, the container body can be folded into halves thus to store the coffee filter chamber inside the container body.
In the latter coffee extractor, a container body is also provided with vertical pleats at a peripheral face of its lower half part, a folding line formed at an upper edge of the vertical pleats, and an annular groove formed at an outer circumferential edge of a stepped part which continuously forms a coffee filter chamber. The container body will be folded at the folding line and the annular groove while being reduced in diameter by means of the vertical pleats thereby enabling the lower half part of the container body to be folded inside an upper half part. In this manner, the container body can be folded with the coffee filter chamber stored therein.
These two proposals aim to reduce a capacity of the coffee extractor into a half by folding the lower half of the container body having a cup-like shape into the upper half, thus making it compact, in order to solve the bulky state in the prior art. However, they have still such problems that the vertical and horizontal pleats must be formed on the peripheral face of the container body and the folding line must be formed at the upper edge of the vertical pleats in order to fold the container body. Further, in the latter proposal, the annular groove must be formed.
Formation of the vertical and horizontal pleats, the folding line, the annular groove, and so on has been inevitable means to be adopted, since synthetic resin material having rigidity has been selected in the two proposals to make the extractors. However, there has been a further problem that because folded configurations are defined by shapes and dimensions of the pleats, the folding line and the annular groove, and positional relations therebetween, and further because the folding operation is promoted through cooperation between the vertical pleats and the horizontal pleats, between the pleats and the folding line, and between the pleats and the annular groove, the folding and expanding operation must be conducted while making a balance between the above described parts.
There has been a still further problem in the above proposals that since the material must be synthetic resin for a reason of forming the pleats and the folding line, the device cannot be simply disposed of among trash in spite of disposable type.
It is an object of the present invention to provide a filter device for coffee and so on, which has excellent storing ability and transportability while containing therein substance to be extracted such as an appropriate amount of coffee, tea or the like, which can easily make extracted drinks of coffee, tea or the like, and which can be simply treated.
It is another object of the present invention to provide a filter device for coffee and so on, which can be stored in a compact shape, which can be easily expanded for use to such a size capable of receiving sufficient amount of hot water to be poured, and that, which can easily and reliably make tasty drinks such as formal coffee without employing extra tools which are annoying in treatment.
It is a further object of the present invention to provide a filter device for coffee and so on, which can be freely folded and expanded having excellent handling performance, which can be manufactured of paper or the like as raw material, and which can be simply disposed of after use without incurring disadvantages such as environmental contamination.
It is a still further object of the present invention to provide a filter device for coffee and so on, which has a rational structure suitable for mass production, and which can enjoy high productivity and excellent cost performance.
In order to attain the above described objects, there is provided according to the present invention, a filter device for coffee or the like comprising a container body consisting of an open frame formed of sheet material having predetermined rigidity, and a blind-end frame including an annular bottom member and connected to the open frame so as to be folded, the blind-end frame being formed of sheet material having predetermined flexibility, and a filter chamber for enclosing substance to be extracted and received in the annular bottom member via a filter, wherein the blind-end frame is adapted to be folded inside the open frame together with the filter chamber.
According to another aspect of the invention, the open frame is formed of sheet material in a tubular shape having predetermined rigidity, and the blind-end frame is formed of deformable sheet material in a tubular shape to which is given shape retaining characteristic having predetermined rigidity and flexibility.
The filter chamber is preferably has an outer diameter which is smaller than an inner diameter of a cup to be applied. The blind-end frame has such a size as surrounding the filter chamber, and the open frame has such a size as surrounding the blind-end frame. By folding the open frame and the blind-end frame at a folding area between them, the filter chamber and the blind-end frame can be stored inside the open frame.
Preferably, the open frame, the blind-end frame and the filter chamber have substantially the same height. When the open frame, the blind-end frame and the filter chamber are folded, they will be contracted into a size of the open frame. In this state, the filter device can be made compact, and easily stored and packed.
According to a further aspect of the invention, the height of the blind-end frame may be substantially twice as high as the height of the open frame, and an upper half of the blind-end frame is attached to an inner peripheral face or an outer peripheral face of the open frame, thus reinforcing the open frame. In this case too, the open frame, the blind-end frame and the filter chamber may have substantially the same height.
The blind-end frame presents a substantially tubular shape when expanded outward of the open frame, and can receive sufficient amount of hot water in use. In the expanded state, the container body may have a varied diameter gradually reduced from the open frame to the blind-end frame into a substantially inverted shape of a truncated cone.
According to a still further aspect of the invention, a reinforcing frame having predetermined rigidity may be formed at a circumferential edge of a bottom of the blind-end frame.
Preferably, the reinforcing frame is extended downward from the bottom of the blind-end frame thereby to integrally form a cup holding frame.
According to a still further aspect of the present invention, the open frame and the reinforcing frame provided at the circumferential edge of the bottom are integrally connected by means of a plurality of connecting pieces. Since the blind-end frame, the reinforcing frame and the open frame are made integral by means of the connecting pieces, a plurality of windows can be formed by stamping, leaving the connecting pieces, in a lower half of the cup-shaped container body having the annular bottom. A body part of the blind-end frame which is flexible and deformable may be attached to the inner peripheral face of the cup-shaped container body thereby to cover the windows from the inside.
By providing the body part of the blind-end frame with the connecting pieces, it has become possible to realize stable folding and expansion of the filter chamber, the blind-end frame and the open frame.
According to a still further aspect of the present invention, the open frame is formed of thick paper having predetermined rigidity, and a body part of the blind-end frame is formed of deformable thin paper provided with shape retaining characteristic having predetermined rigidity and flexibility.
According to a still further aspect of the present invention, the open frame is formed of non-woven fabric having predetermined rigidity, and a body part of the blind-end frame is formed of deformable non-woven fabric provided with shape retaining characteristic having predetermined rigidity and flexibility.
The filter device according to the present invention can be used as the filter device of the dripping type by expanding the container body into a cup-like shape and mounting it on a coffee cup or the like, into which hot water is simply poured. When the filter device is not in use or prior to use, the blind-end frame of the container body can be pushed into the open frame together with the filter chamber. Therefore, the filter device has such advantages that it can be contracted into a compact shape, easily packed, and will not take spaces for storing, transporting or displaying in shops etc.
Moreover, the filter device according to the present invention can be simply and easily manipulated for contraction by pushing the blind-end frame into the open frame by means of flexibility of its body part, and can be also smoothly expanded for use without any resistance.
Further, since all the area of the body part is deformable, there is no need of providing a specific folding position such as the folding line, pleats, etc. in the conventional cases. Therefore, it is advantageous that smooth contracting and expanding operation can be realized according to the invention.
Other objects, features of the present invention will be made apparent from the following description with reference to the accompanying drawings.